Public reporting burden for this form is estimated to average 8 minutes per response. The burden estimate includes the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and submitting the form. This collection of information is mandatory. You are not required to respond to this collection of information unless it displays a valid OMB control number. Send comments regarding the accuracy of the burden estimate and any suggestions for reducing the burden to: to the Mine Safety and Health Administration, U.S. Department of Labor, Office of Standards Regulations and Variances, 1100 Wilson Blvd., Arlington, VA 22209, Paperwork Reduction Project (1219-0040). NOTE: Do not send your completed form to this address.